Hardware Hacking 25The tape & Plastic-Dip treatment serves several functions:
- It strengthens the connections between the wires and the Piezo-disk.
- It insulates the disk from electrical shorts, and prevents hum when you
touch it. - It waterproofs the contact mike, so you can use it to record underwater
sounds, freeze it in ice-cubes, dangle it in a drink, etc. - It deadens slightly the pronounced high-frequency resonance of the
disk (similar to the effect of gaffing tape on the head of an unruly snare
drum.) - It looks really cool and is a fun treat after all that soldering.
What to try with your contact mike
Contact mikes are great for greatly amplifying hidden sounds in everyday
objects. The trick is making positive physical contact with the vibrating object.
Use double-stick tape or Blu-tak to attach the mike to the surface of vibrating
objects. Try: guitars, violins, drums, pots & pans, wrists & knees, foreheads,
pinball machines.
Use small spring clamps to hold things to the contact mike. Try: strips of metal,
gaffing tape, rulers, popsicle sticks.
“Terminal strips” are used to make electrical connections in lamps and other
appliances. They can be salvaged from discarded appliances or bought from any
number of sources, including Radio Shack, DIY shops like Home Depot, and on-
line electronic surplus retailers. Cut terminal strip into small section and clamp
onto the mike with a spring clamp. Insert thin objects into the terminal openings
and hold in place by tightening the screws. Try: Slinkies, springs, loose guitar
strings, toothpicks, satay sticks, broom straws, porcupine quills, cactus needles.